Access control is required for secure communication in most prior art wireless radio communication systems. As an example, one simple access control scheme might comprise: (i) verifying the identity of a communicating party, and (ii) granting a level of access commensurate with the verified identity. Within the context of an exemplary cellular system (e.g., Universal Mobile Telecommunications System (UMTS)), access control is governed by an access control client, referred to as a Universal Subscriber Identity Module (USIM) executing on a physical Universal Integrated Circuit Card (UICC) (also referred to as a “SIM card”). The USIM access control client authenticates the subscriber to the UMTS cellular network. After successful authentication, the subscriber is allowed access to the cellular network. As used hereinafter, the term “access control client” refers generally to a logical entity, either embodied within hardware or software or combinations thereof, suited for controlling access of a first device to a network. Common examples of access control clients include the aforementioned USIM, CDMA Subscriber Identification Modules (CSIM), IP Multimedia Services Identity Module (ISIM), Subscriber Identity Modules (SIM), Removable User Identity Modules (RUIM), etc.
Traditionally, the UICC enforces a trusted boundary for one or more USIM (or more generally “SIM”) access control clients. The UICC is manufactured and “hardcoded” with a SIM i.e., once programmed, the UICC cannot be reprogrammed. If a user wants to authenticate to a cellular network using a different SIM, the user must physically exchange the SIM card in the device with a different SIM card. In response to these physical limitations, some devices have been designed to house two SIM cards at the same time, known as Dual-SIM phones. However, Dual-SIM phones do not address the fundamental physical limitations of SIM card devices. For example, information stored within one SIM card cannot be easily consolidated with information stored within another SIM card. Existing Dual-SIM devices cannot access the contents of both SIM cards simultaneously. Lastly, accessing a SIM card requires a perceptible and non-trivial amount of time for the user; switching between SIM cards to transfer information is undesirable and reduces user experience, and this limitation is present in both traditional and Dual-SIM devices.
Accordingly, new solutions are needed to increase flexibility in accessing multiple access control clients. Ideally, such solutions should allow for sharing of common user data between the multiple access control clients to enhance the user's experience. Moreover, the improved methods and apparatus should allow for seamless switching between the multiple access control clients to improve a user's access and use of cellular services.